Backfiring and AIS

[crazygaucho]

My bike was backfiring on deceleration way too much and with the 4-2-4 nasty boys installed was worse and louder, after reading the simple instructions of this website plugged the AIS and voila what a difference !!!!!!!!!! I still have some but improved about 80%

 

I will need to synchronize my carburetors but before I buy anything I will try to see how is done

 

just want to say thanks to the group the info here is priceless !

[bongobobny]

Exhaust gaskets can also cause backfiring, but yes the AIS can cause a lot of it!

[billmac]

Best thing I've bought for my bike is a carbtune. After the first time it take about ten minutes to sync the carbs and by friends with ventures also let me do theirs. I check mine 2-3 times a year and I learned you need a long Phillips screw driver and a hot engine.

[Hotrod]

Check your Y pipe connections on both sides where they are crimped to the main pipe.Mine had a leak and were sucking in air and causing popping after I had plugged the AIS.Yamaha crimped these instead of welding and they leak.I used a putty epoxy like JB Weld and kneaded it into a small like rope and wrapped the pipe and pushed it into the gap and waited till the next day till it hardened.It has held for over 5 years with no more popping.

[V7Goose]

My bike was backfiring on deceleration way too much and with the 4-2-4 nasty boys installed was worse and louder, after reading the simple instructions of this website plugged the AIS and voila what a difference !!!!!!!!!! I still have some but improved about 80%

 

I will need to synchronize my carburetors but before I buy anything I will try to see how is done

 

just want to say thanks to the group the info here is priceless !

This reply is mainly for other relative newbies on this site that might get the wrong idea from this new thread...

 

First, the AIS NEVER causes exhaust popping or after-fire. A properly setup and tuned 2nd gen will never do this, so there is something significant wrong with your bike. By disconnecting the AIS you have simply chosen to hide it instead of fixing it. You are also causing pointless and unnecessary pollution. For anyone who actually cares to lean more, I have covered all of this in great detail in older threads, so do some research (but you will have to go back several years).

Goose

[Moped]

This reply is mainly for other relative newbies on this site that might get the wrong idea from this new thread...

 

First, the AIS NEVER causes exhaust popping or after-fire. A properly setup and tuned 2nd gen will never do this, so there is something significant wrong with your bike. By disconnecting the AIS you have simply chosen to hide it instead of fixing it. You are also causing pointless and unnecessary pollution. For anyone who actually cares to lean more, I have covered all of this in great detail in older threads, so do some research (but you will have to go back several years).

Goose

 

 

You are 100% correct.

[steamer]

Goose is right on this. The problem is usually caused by an exhaust leak or carb problems. in my case it was several pin hole leaks in the "y" pipes. The "y" pipes are made out of a milder steel then the front pipes, why, I don't know, but they will rust and get thin over time. You need to take good care of these pipes because they cost something in the neighborhood of $450.00 each. If not the pipes then maybe your carbs need some adjustments. plugging the AIS is a waste of time.

[MikeWa]

Goose is right on - except a bad diaphragm in one of the AIS valves can cause popping on whichever side it controls.

In that case the valve should be repaired. Not covered up.

 

Mike

[vzuden]

As everyone has said AIS is not the problem or cure. I believe the first step should be a carb sync as long as the fuel as been treated regularly with Sea Foam